Feed mechanism for sewing machines



A. A. MERRITT FEED uacmuismfon sswme MACHINES 4 Sheets-Sfieet 1 Filed Nov. 22, 1921 QIQ NQQQ Nb mm wm Q A. A. MERRITT FEED MECHANISM FOR SEWING MACHINES July 13 1926.

Filed Nov. 22. 1921 4 Sheets-Sheet 2 lfWENToR How/w July 13 1926.

Filed Nov. 22. 1921]; 4 Sh'eets-Shet 5 Hille aftozucq July 13,1926.

- A. A. MERRITT FEED IIBCHIQNISM FOR SEWINGMACHINES- Filed Nliv. 22, 1921 4 Sheets-Sheet 4 fit) Patented Jarvis, was.

UNITED STATES mm orrics. i

ARTH'UR'A. MERRITT, OF VYOHCESIER, MAEEACHUSETTS, ASSIGIl'DR E WILLGOX &

GIBBS SERVING MACHINE CO., 65 NEW Y9; K, Y1,

YORK.

a consort-Arron on NEW FEED MECHANISM res snwrne Mecrrrujns.

Application filed November 22, 1921. Serial No 517,060. I

This invention relates to feeding mechan ism for sewing machines and though especially designed for use in what is cominercially known as the l' illcox 8: Gibbs Sewing Machine Companys Feldlock Mm chine, partly shown for example in Merritt Patent No. 1,253,507 dated Jan 15, 1918, is applicable to sewing machines generally.

It is common in some types of sewing 'niach'ines, as illustrated for example in the aforesaid Merritt patent and also in Merritt Patent 1,0 li,658, dated October 15, 1912, relating to what is commercially known as the lVillcoX & Gibbs Sewing Machine Companys Flatlock llfachine, to employ feed mechanisms in which the feed-dog or member, is rigidly attached to and'projects beyond one end of an approximately horizon" tal lever which simultaneously reciprocates longitudinally and oscillates vertically on a l horizontal. fulcrum or axis. In such structures there is considerable of what'may be called ,overhang of the feed-dog beyond the fulcrum, that is to say, the feed-dog projects or is located considerably beyond the fulcrum of its lever, as shown by the patents aforesaid. When the feed-dog in s1 reh structures is at the limit of its'upward movement with the presser-foot resting against the feed-dog or the interposed work, the upper surface ofthe feed-dog is practically horizontal or parallel with. the surface of the cloth-plate through which said dog projects; but as the gripping points orteeth of feed surface or surfaces of said feed-dogi begin to rise through their slots in the clothplate they are inclined downward in the direction of feed so that the end of thefeed surface nearest the operator first engages,- lhe work and grips it against the pressen' foot, the incline gradually diminishing as the feed-dog rises to the limit of its upward movement. Then in the descending movement of the feed-dog there is a gradual reverse tilting thereof and disengagement of its feed surface with the work, just the reverse of what happens in the upward movement of the feed-dog. In other w rds,

the travel of the feed surface above the cloth-plate is in a curved path bowed up wardly from the surface of the throat-plate so that the teeth of the feed surface progressively engage and disengage the work with the maximum number of teeth simulthereto.

taneously in engagement with the work at the very top of the movement of the feeddog. Such variation in the extent or area of gripping surface applied to the work tends to an unevencontrol of the work or fabric in the feeding thereof and to an uneven feeding; particularly when operating upon sleazy, flexible, or soft fabric such as knit goods An obgect of the'present invention is to avoid theaforesaid varying, or increasing both endsthereof, preferably through pivta]. connections to both said ends. Another object is the provision of driving means bv which such pivots at both ends of the feed dog are caused to lravel'in parallel paths of movement.

lVith the overhang of the feed-dog in prior structures such as hereinbefore men- 7 tioned there is some springer yield of said dog under the downward pressure exerted by the presser-foot and occurring particularly when working upon heavy fabrics, such overall material, khaki cloth, duck and canvas. Such spring tends to throw the gripping surface of the feed-dog out of proper alinement and detract from the effectiveness of the grip of said surface upon the'work to be fed. Another object is to overcome such objectionable spring or yield.

by firmly supporting the feed-dog at both ends throughout its engagement with the work in feeding the same.

Another object is the provision'of feed ing mechanism of the character indicated capable of operating efiiciently at high speed, such for example as required in making three thousand or more stitches per ninute.- I,

The aforesaid and other objects and advantages are attained by what is now believed to be the preferred embodiment of the invention illustrated in the accompanying drawings whereof Figs. 3 to 16 inclusive are on practically a full size scale, while Figs. 1 and 2 are on a somewhat reduced scale, and wherein Fig. 1 is a longitudinal vertical sectional iew through the horizontal work supporting part of the work arm of the machine showing the improved feed mechanism and other parts applied thereto;

Fig. 2 is a top plan view of the horizontal work supporting part of the arm of Fig. 1 with its cover removed and showing the feed-dog but omitting other operating parts within the free end of the arm;

3 is .a vertical section on line 33 of Fig. 1, including a showing of part of the work arm extending upward from that illustrated in said Fig. 1;

Figs. Land 5 are vertical sections on lines el 4. and 55 respectively of Fig. 1;

Fig. 6 is a plan view of the tree end of the horizontal work supporting portion of the work arm, showing particularly the work plate;

Fig. 7 is a side elevation of the end of the work arm shown in Fig. (i with the slide cover of an opening through the side of the arm removed, the parts within the arm visible through said opening not being shown;

Fig. 8 is a fragmentary front view of the. portion of the work arm shown in Fig. 3;

Fig. 9 is a vertical section on line D9. of Fig. 8;

Fig. 10 is a detail view of an adjusting gear and rack-plate which latter carries the pivot pin or fulcrun'i of a. vertical lover of the feed driving mechanism;

Fig. 11 comprises detail views of the link which is connected to one end of the feeds;

Figs. 12, 13 and 1 1 are detail views of other parts;

Fig. 15 comprises several detail views of the feed-dog or member and the pivot pins at opposite ends thereof;

Fig. 16 comprises detail views of a linl: and one of the pivot pins connecting the two horizontal feed levers at one end there of; and I Fig. 17 is a diagrannnatic schematic v'ew showing by the larger full line ellipses or circles paths of travel when the feed mechanism is adjusted to form stitches of maximum length, and showing by smaller dotted line ellipses or circles corresponding paths of travel when the feed mechanism is adjusted to form stitches of minimum length.

In the drawings the operating parts are illustrated in conjunction with a fee-dotithe-arm hollow work arm of the type more fully illustrated in Merritt Patent 1,011,652, dated Qctober 15, 1912, said arm including an upper horizontally extending part 20, a portion only of which is shown in Fig. 3, a vertically depending part 21, Figs. 1, 3, 8 and 9, and a horizontal work supporting part 22, Figs. 1, 2 and 3, having a free end oil which the finished work is fed. Three screws 23, only two of which are shown in Fig. 1, extending upward through openings 2 1, Fig. 2, in the wall of part 22 of the arm. rigidly secure said part to the lower end of the vertically depending part 21 of the arm. In the present machine the part 22 of the arm is made somewhat deeper than the corresponding part in the patents aforesaid to accommodate parts of the feed mechanism of this invention. At the free end of the part 22 of the arm there is a. U-shaped cloth-plate frame 25 properly positioned by dowel pins 26, 26 projecting upwardly from the wall of arm 22, Fig. 2, and secured by two screws (not shown) adapted to extend upward through open- 27, 27 in the wall of the work arm and at their upper threaded ends engaged screw threaded openings (not shown) in the under side of the frame 25. lVork plate or cloth plate 28 is applied over frame 25, properly positioned thereon by dowel pins 29, 29 pro-- jccting upwardly from the frame and secured in place by three screws 29', Fig. 6. A removable cover 80 for the part of the work arm is beveled at its edge at one end to engage beneath the undercut edge of cloth-plate 28 1) and at its other end is secured in place by a bolt latch 81 having a conical pointadapted to seat in a conical depression in the wall of part 21 of the work arm.

Fig. 1 shows a number of operating parts having to do with stitch formation and which are shown in position relative to the improved feed mechanism but which constitutes no direct part of said mechanism or of the present invention, and which are substantially the same as corresponding parts in prior patents. Thus there is a looper lever 30, a looper carrier 31 pivotally mounted thereon by a pivot screw 32 and carrying two loopers one for each of the needles not shown. The looper carrier 31 is held in its nora operative position relative to the looper lever, as shown in Fig. 1, by the latch shown at 34. in said figure and of a construction shown in the prior patents herein mentioned; but said carrier with its loopers may be swung forward in F 1, about pivot 32 and through the opening 35, 7, in the. front wall of the work arm said opening having a slide cover 85, 36 is a loop spreader having a tail piece 37 pivoting on a screw pivot 38 which engages a supporting bracket arm 39 fastened to and projecting from the inner face of one of the upright walls of the arm. A roller 40 depending from tail piece 87 en} ncense gages a cam-groove of a part 41, as further shown in Osterhout Patent 1,253,518, Jan. 15, 1918, said part ll being secured to the looper lever 30, whereby movement of the latter imparts sidewiseswinging movement to the loop spreader 36 about its pivot 38. i2 is a loop-check and needle guide supported from one of the side walls otthe arm and such as shown in Osterhout Patent horizontal lever at plates l6 and 4,7. At its other end said lever bears upon a horizontal cross-bar or support 48. 49 is a rotatable tulcru 0 block in which thelooper lever 39 fits and moves loi'igitudinally and which turns with the lever in the compound movement thereof causing the points of the loopers to travel in elliptical paths. i

Coming now to the parts feed mechanism of the present invention 50 is the upper horizontal feed lever fulcrumed to turn and move horizontally upon a pivot pin 51 which is supported at opposite ends in openings through the side walls of part of the work arm. Two bearing blocks 52 embrace the fulcrum pin 51 and are in turn embraced by an elongated capped bearing opening 1530f the lever 50, the cap plate 90 of said bearing being countersunk into a recess on the underside of lever 50, with shoulders 91, 91 at opposite ends of said recess closely fitting the endcdges of said plate. Countersunk screws 92, 92 secure plate 90 in place. lVith considerable upward pressure of the feed-dog, curring particularly when operating upon heavy work, there is a tendency to bend lever 50 downward at opposite sides of its fulcrum 51 and with a cap plate held, in place merely by screws, as shown for example in Figs. 6 and 11 of Merritt Patent 10 M558, dated Oct. 15, 1912, there is likely to be a yield or give of the lever to the" extent of the looseness in tit oi the screw threads and bodies of the screws in vtheir holes. structure by the cooperation of 91 with the ends of plate 90. v 7

At its right hand end Fig. 1, lever is pivoted by pin 54 to the lower end of a vertical lever 55 which is fulcrumed to turn and to move longitudinally on the inner reduced end of a pivot screw 56, Fig. 3, the threadedportion ofwhich engages a screw threaded opening through a rack in a plate 63,

By means V 2, said end of the lever working between parallel bars or constituting the wvith it the pivot This is overcome in the present shoulders which-it is joined. Pivot plate 57, 3 and 10, and the head of said screw being vertically movable in a countersunk vertical slot 58 in the -iront wall or the vertical part of the work arm Figs. 3 and 8. The inner end ofpivot screw 56 is embraced by two bearing blocls 58 Fig. 1, which are in turn embraced by an elongated capped hearing opening of lever Gear teeth along one vertical edge or ack olate 5? are engaged by a gear 1- wheel (30, l? 9 and 10 secured to ashort shaft 61 to the outer end of which is fixed a wheel 62, rotatable in a circular opening Sand 9', secured by a screw 6% in an opening through the front wall oi the vertical part 21 of the work arm.

Screwfietenga es a block 65 9 secured c, D 7 t: 7

within'the verti. part of the work arm by screws, 66 and 67. e

The POSltlOil of the pivot screw 56 de- .termines the length of feed movement of the feed-dog and hence the length of stitch produ d. llormall said screw is turned i 1 a 1 1 to pc 11 to draw llCK plate o( into tight engagement with thewall of part 21 of the work arm, Fig. 8, thus locking the pivot in the desired position of operation. To adjust the position of the pivot screw and correspondingly change the length of stitch produced, said screwv is first turned in reverse direction sui'licient to loosen plate 5'7, and the wheel 62 is then rotated the de sired mount, which may be accurately determinedby the scale thereon, F 8, cor respondingly rotating the gear wheel (30 in engagement with the teeth of thoracic plate, raising or lowering said plate and screw 56, the head of the or own, as the case may When the parts have latter n'ioving up be, in the. slot 58.

beenthusadjusted to the desired position,

thepivot screw 56 is locked in position by again rotating the same to draw the rack plate into tight engagement with the wall of the work arm.

70 is the feed-dog shown as having a teed-surface consisting of four sections or parallel rows of teeth uovable in corresponding slots in the cloth-plateQS. At its front end, that'is its right-hand end in l, saidfeed dog is pivoted by pivot screw 71 to the end 01" teed lever 50. .At its other or rear end said dog is pivoted by pivot screw 72 to the upper end of a wertically disposed link l3 the vertical flat side edges oil which make close sliding e gagement with the side walls of the work arm (see Fig.5} to prevent sidewise move ment' of the link and end of the dog to screw T l connects the lower end of link 1 3. to one end of a teed lever T5, said lever extending along thebottom of part 22 of the work arm and at itslotherend being joined by pivot screw 6 t e lower; end'ot a link 7'7 the upper end of which is connected by pivot screw 78 to the upper feed lever 50. Intermediate of its ends lever 75 is fulcrumed on a horizontal screw pivot pin 79 which spans the space between and is secured in two arms of an inverted Ushaped bearing block 95, the lever 75 passing through said block in the space between the arms thereof. Block 95 has a cylindrical exterior surface fitting rotatably in the curved recesses 96 and 97, Fig. 2, in the inner surfaces of'the vertical side w lls of the work arm. The hereinbefore mentioned block d9, which has a cylindrical exterior surface, also rotatably fits in said recesses 96 and 97 above and resting upon the block 95, as shown in Figs. 1 and a. A circular plate 98 fits in said curved recesses above block l9 and over lever and is engaged and secured in place by screws 99, 99 through the side walls of the work arm, said plate thus holding the parts beneath it down to proper position during operation thereof.

In the operation of the feeding mechanism, the vertical lever 55, being simultaneously reciprocated longitudinally and oscillated laterally on its pivot screw or fulcrum 56 by driving connections (partly shown in Fig. 3) such as shown in the aforesaid Merritt Patent l,0ll,658, actuates upper feed lever through pivot connection 5st imparting to said lever simultaneous longitudinal reciprocating and lateral oscillating movements on its pivot pin or fulcrum 51. Lever Sta-acting through pivotal connection 7l, to the forward end of feed-clog 70, imparts to said dog continuous movement in an elliptical or circular path, raising and lowering the feed surface of said dog through the work plate to engage and disengage the work and moving said dog longitudinally while in engagement with the work to feed the same. The lower feed lever 7 5, actuated at one end through the link connection 77 to lever 50, is thereby oscillated on its fulcrum '79, and acting at its other end through link connection 7 3 raises and lowers the rear end of the feed-dog while at the same time, because of the freedom of the link 73 to vibrate on its pivot 74, leaving feed-dog 7 O unhampered in making its longitudinal feed movements communicated the "eto by lever 50 as already described.

Fig. 17 diagrams or plots the driving connections to the feed-dog and differences of movement for different adjustments of the driving connections for the formation of different lengths of stitch. With the pivot pin or fulcrum 56 set to the limit of'its up ward adjustment, as shown by full linesin Fig. 17, the driving connections of the feeddog will be actuated on paths of movement shown by the full line circles or ellipses and resulting in stitches of maximum length. With the pivot pin or fulcrum 56 set to the limit of its downward adjustment, as shown by dotted lines in Fig. 17, the corresponding paths of movement are shown in dotted lines resulting in stitches of minimum length. As shown, each dotted line ellipse and its corresponding full line ellipse have the same length of vertical axis, representing up and down movement of the feed-dog. But said ellipse differ as to length of horizontal axis representing forward and backward movement, that part of such movement which is above the surface of the clothplate representing and determining the length of each forward feed movement imparted to the work and hence the length of stitch produced. It will also be seen that the vertical movement at both ends of the feed-dog is the same for any given adjust ment, so that in all positions of movement, and whatever the adjustment as to length of stitch, the vertical movement of the feedsurface of the dog is always the same and will at all stages of its engagement with the work stand parallel to the surface of the cloth-plate.

hat I claim is:

1. In a sewing machine, the combination of a feed-member for engaging and feed ing the work, and driving means therefor including two relatively movable members connected respectively to opposite ends of said feed-member said driving means being arranged and adapted to positively impart like upward and downward and forward and backward movements to both ends of said feed member.

2. In a sewing machine, the combination of a feed-member for engaging and feeding the work, and driving means therefor including two members pivotally connected respectively to opposite ends of said feedmember said driving means being arranged and adapted to impart to the feed member through said two members like upward and downward and forward and backward movements to both ends of said feed member.

3. In a sewing machine, the combination of a cloth-plate, a feedmember having a feed-surface adapted to operate through and above said clothplate, and driving means including two relatively movable members connected respectively to opposite ends of said feed-member said driving means being arranged and adapted to impart to the feed member through said two members like upward and downward and forward and backward movements to both ends of said feed-member as to that part of its travel during which its feed-surface is above the cloth-plate.

l. In a sewing machine, the combination of a cloth-plat a feed-member having a feed-surface adapted to operate through and above said cloth-plate, and driving means including two members pivotally con- {weasel feed-membersaid driving means being arranged and adaptedto impart to the feed member through said: two members like upward and downward and forward and backward movements to both ends of said feed-member as to'that part of its travel during which its feed-surface is above the. cloth-plate. r a

In a sewing machine, the combination of a clotlnplate, a feed-member having a feedsurfac means including two relatively movable members connected respectively to opposite ends of said feed-member said driving means being arranged and adapted to impart to the feed member through said two members like upward and downward and forward and backward ,movements to both ends of said feed-member during the work- I feeding part ofits travel.

6. In a sewing machine, the combination of a elot-lnplate, itfGGCl-lllelllbQY having a feed-surface adapted to operate through and above said cloth-plate, and driving means including two levers nvotally connected respectwely to opposite ends of said ranged and adapted to positively impart likempward and downward and forward and backward movements to both ends of said feed-member as to that part of its travel during which its feed surface is and downward and forward and backward movements to both ends of said feed-memher during the work-feeding part of its travel.

S. in a sewing machine, theeombination of a work arm having an approximately horizontal free ended work supporting part, a feed-member, and driving meansfor said feed-member including two 'members extending along said work supporting part of the arm and connected respectively to opposite ends of the feed-member saidvdriving means being arranged and adapted to impart like movement to both ends of said feed-member. v r

9. In a sewing machine, the combination of a cloth-plate, a feed-member having a feed-surface adapted to operate through and above said cloth-plate, and driving m ans including two levers pivotally connected respectively to opposite ends of said feed-member said driving means being a1;

"cloth-plate.

adapted to operate through and above said cloth-alate, and dnvin 1 member said driving means being ar-' horizontal free ended work ranged and adapted to impart to said feed member through said two levers like upward downward and forward and backward movements to both ends of said feed-member as tofithat part of its travel during whichits feed-surface is above the 10. In a sewing machine, the combination of a work arm having an approximately horizontal f ee I ended work supporting part, a cloth-plate mounted on said arm at or near the free end thereof, a feed member having a feed-surface adapted to operate through and above said cloth-plate, and driving means including two levers pivotallyconnected respectively to opposite ends of said feed-member said driving means be ing'arranged and adapted to impart to said feed member through said two levers like upward and downward and forward and backward movementsto both ends of said feechinember as to that part of its travel during which its feed-surface is above the cloth plate.

ii. In a sewing machine, the combination of a work arm having an approximately horizontal I free ended work supporting part, a feed-member at or near the free end of said arm, and driving means for said feed-member including an upper and a lower feed-lever extending along said work supporting;part of the arm and connected respectively to opposite ends of the feedmember. 1

12. In a sewing machine, the combination of a workarm iaving an approximately supporting part, a feed-member at ornear the free end of said arm, and driving means for feed-member including an upper and a lower feed-leverextending along said work supporting part of the arm the upper feed lever being pivotally connected directly to one end'of the feed-member and the lower feedlever being pivotally connected to the oil er end of the feed-member through the intermediary of a link-member.

13. In a sewing machine, the combination of a work arm: having an approximately horizontal free ended work supporting part, a cloth-plate mounted on said arm at or near the free end thereof, a feed-member having feed-surface adapted to operate through and above the surface of said cloth-plate,

and driving means for said feed-me1nber in cluding an upper and lower feed-lever extending along said work supporting part of the armand connected respectively to opposite ends of the feed-member said driving 'means being arranged and adapted to im part like movement to both ends of said feedmember as to that part of lts travel during which its feed-surface is above the clothplate.

14. In a sewing machine, the combination of a work arm having an approximately horizontally free ended work supporting part, a cloth-plate mounted on said arm at or near the free end thereof, a feed-member having a feed-surfacc adapted to operate through and above the s face of said clothpiate, and driving means for said feed-member including an upper and a. lower feedlevcr extendinp along said work supporting partof the arm the upper feed-lever being pivotally connected directly to one end of the feed-member and the .lower feed-lever being pf 'otally connected to the other end of the feed-member through the intermediary of a link-member and said driving means being arranged and adapted to impart like movement to both ends of said feed-member as to that part of its travel during which its feed-surface is above the cloth-plate.

15. In a sewing machine, the combination of a work arm having an approximately horizontal free ended work supporting part, feed driving means including an upper and a lower feed-lever both extending along said work supporting part of the arm, and a feedmember located at or near the free end of said arm said feed-member being at one end pivotaliy connected to and supported from the end of one of said feed-levers and at its other end being pivotally connected and supported from the end of the other of said feed-levers.

16. In a sewing machine, the combination of a work arm having an approximately horizontal free ended work supporting part, feed driving means including an upper and a lower feed-lever bot-h extending along said work supporting part of the arm, and a feedmember located at or near the free end of said arm said feed-member being at one end pivotally connected directly to and supported from the end of the upper feed-lever and at its other end being pivotally connected to and supported from the end of the lower feed-lever through the intermediary of a link.

17. In a sewing n'iacliine, the combination of a feed-member for engaging and feeding the work, and driving means therefor including two relatively movable members connet-ted respectively to opposite ends of said feed-member and by which the latter is supported and actuated, like movement imparted to both ends thereof during that part of its travel in which it is feeding the work.

18. In a sewing machine, the combination of a feed-member for engaging and feeding the work, and driving means therefor including two relatively movable members con nected respectively to opposite ends of said feed-member and by which the latter is both supported and actuated said driving means being arranged and adapted to impart to said feed member through said two members like upward and downward and forward and backward movements to both ends of said feed-member during that part of its travel in which it is feeding the work.

19. In a sewing machine, the combination of a feed-member operating in an approximately horizontal position, and driving means therefor including approximately horizontal upper and lower feed-levers, said feed-member being pivotally connected to and supported at one end from the upper feed-lever and pivotally connected to and supported at its other end from the lower feed-lever.

20. In a sewing machine, the combination of a feed-member for engaging and feeding the work, and driving means including two levers pivotally connected respectively to opposite ends of said feed-member and through which pivotal connections said feed-member is supported by said levers and also actuated by said levers to impart to said feed member four-motion feed movements.

21. In a sewing machine, driving connections including a lever having an opening in one side thereof, bea ring positioned in said opening and constituting a fulcrum for said ever, the work imposed upon said lever in operation tending to bend the same in a manner to contract said opening in the side of the lev r, and a cap plate secured to said lever and spanning said opening at the open side thereof said plate closely fitting between two shoulders on the lever opposed to the end edges respectively of the, plate and thus resisting contraction of the opening by the work imposed on the lever.

22. In a sewing machine, the combination of a feed-meinber operating in an approxi mately horizontal position, two approximately horizontal and approximately parallel feed-levers one. connected to and supporting said feed member at one end thereof and the other feed-lever connected to and supporting said feed-member at its other end, and means actuating said feed levers to impart feed movement to said fecdmember.

23. In a sewing machine, the con'ibination of a feed-member operating in an approximately horizontal position, two approximate- 1y horizontal and approximately parallel feed-levers connected at corresponding ends to opposite ends respectively of said feedmember and thereby also supporting said feed-member at both ends, and means actuating said feed-levers to impart feed movements to said feed-member.

In testimony whereof I have signed this specification.

ARTHUR A. l-IERRITT. 

